More than a few people noticed Intel's roadmap originally slated 45nm Penryn desktop quad-core processors for January, only to have the company change the hard launch date to a not-so-firm "Q1 2008." So what happened? In a series of interviews, the tale of quad-core Penryn began to unfold.

Processor engineers, speaking on background, detailed the problem. "Intel is very sensitive to mean time to failures. During a simulation, at high clock frequencies, engineers noticed an increase of potential failures after a designated amount of time."

He continues, "This is not acceptable for desktop customers that require longterm stability. It's a showstopper."

Previous reports of errata degrading the L2 and L3 cache performance were described as "false" -- desktop Penryn processors do not even have L3 cache. Microcode and BIOS updates issued by Intel since November do not fix or address the "showstopper" bug affecting the launch of the quad-core Q9300, Q9450 and Q9550 processors.

The condition does not affect Xeon quad-core processors. Xeon uses a different stepping than the quad-core processors, which fixes this simulated condition. The quad-core 45nm Extreme Edition processor launched in November is also unaffected.

The company would not detail when the processors, originally scheduled for a January 20 launch but announced at CES last week, will see the light of day. Conservative estimates from ASUS and Gigabyte put the re-launch sometime in February. Intel completely removed its January 20 launch from its December 2007 roadmap and has not issued a new roadmap since.

Intel spokesman Dan Snyder says more. "We publicly claimed we will launch its 45nm mainstream processors in Q1 2008, and that's exactly what we did." In fact, the company announced 16 new 45nm processors last week; most of which already shipped to manufacturers -- with the exception of the quad-core desktop variants affected by the showstopper simulation bug.